1Dzip is a compression program with the special purpose of compressing 2Quake .dem files. More information on dzip can be found at 3http://www.planetquake.com/sda/dzip/ 4 5Dzip was originally written by Stefan Schwoon <schwoon@in.tum.de> and 6has since been updated and expanded by Nolan Pflug <radix@planetquake.com>. 7 8Dzip makes use of the zlib library copyrighted by Jean-loup Gailly 9(gailly.net) and Mark Adler (www.alumni.caltech.edu/~madler). More 10information on zlib can be found at the zlib home page at 11http://www.zlib.org/ The source download includes the zlib files, they 12have been slightly modified from the original version. All changes are 13marked with a comment containing "Dzip" and all were made just to 14reduce program size by a little bit. 15 16 17Compilation instructions: 18 19Compiling Dzip itself is very straightforward; 20an example Makefile for gcc on linux or solaris is included. 21 22* For Solaris (or big-endian machines in general), it is necessary to define 23 BIG_ENDIAN. 24 25 26Technical information: 27 28Dzip's demo compression operates in two stages. The first stage takes a 29demo file and converts it into some intermediate format. The second stage 30applies standard zip compression (making use of zlib) to the intermediate 31format. 32 33The objective of the first stage is therefore to produce an intermediate 34format such as can be compressed well by the second stage. Loosely speaking, 35the first stage removes entropy from the .dem file format. I won't go into 36the details of the first stage here, but if you're interested, make sure 37to look in encode.c. 38 39Copyright notice: 40 41 (C) 2000-2002 Stefan Schwoon, Nolan Pflug 42 43 This software is provided 'as-is', without any express or implied 44 warranty. In no event will the authors be held liable for any damages 45 arising from the use of this software. 46 47 Permission is granted to anyone to use this software for any purpose, 48 including commercial applications, and to alter it and redistribute it 49 freely, subject to the following restrictions: 50 51 1. The origin of this software must not be misrepresented; you must not 52 claim that you wrote the original software. If you use this software 53 in a product, an acknowledgment in the product documentation would be 54 appreciated. 55 2. Altered source versions must be plainly marked as such, and must not be 56 misrepresented as being the original software. 57 3. This notice may not be removed or altered from any source distribution. 58 59 Stefan Schwoon Nolan Pflug 60 schwoon@in.tum.de radix@planetquake.com 61 62